The present invention relates to the lid knob of cookers such as pans, pots and others, and more particularly the lid knob of a pressure cooker which has a whistle activated by boiling within the pan and further functions to open and close a steam hole.
Pressure cookers, i.e., pans which keep the steam from leaking outside and thus heighten the pressure and the boiling point within them, thereby shortening cooking time have been used for some time. Ingredients are put into the pan when the water is fully boiled. If a boiling informer were furnished, overboiling would be avoided and fuel would be saved.